Rate of change in a real-world situation

The rate of change is how much the amount changes in each time period. It is negative if the amount goes down.

1. A candle is 20 cm tall and burns down 6 cm every hour. What is the rate of change, in cm per hour? Write a negative number if it decreases.
2. A candle is 8 cm tall and burns down 8 cm every hour. What is the rate of change, in cm per hour? Write a negative number if it decreases.
3. A candle is 27 cm tall and burns down 7 cm every hour. What is the rate of change, in cm per hour? Write a negative number if it decreases.
4. A hiker is 20 km from camp and walks toward it at 4 km every hour. What is the rate of change, in km per hour? Write a negative number if it decreases.
5. A jar holds 54 coins and 4 more coins are added each week. What is the rate of change, in coins per week? Write a negative number if it decreases.
6. A jar holds 12 coins and 7 more coins are added each week. What is the rate of change, in coins per week? Write a negative number if it decreases.
7. A pool holds 69 L of water and a hose adds 2 L every minute. What is the rate of change, in L per minute? Write a negative number if it decreases.
8. A hiker is 68 km from camp and walks toward it at 12 km every hour. What is the rate of change, in km per hour? Write a negative number if it decreases.
9. A jar holds 41 coins and 13 more coins are added each week. What is the rate of change, in coins per week? Write a negative number if it decreases.
10. A hiker is 78 km from camp and walks toward it at 2 km every hour. What is the rate of change, in km per hour? Write a negative number if it decreases.
11. A hiker is 87 km from camp and walks toward it at 15 km every hour. What is the rate of change, in km per hour? Write a negative number if it decreases.
12. A hiker is 97 km from camp and walks toward it at 5 km every hour. What is the rate of change, in km per hour? Write a negative number if it decreases.
13. A jar holds 50 coins and 9 more coins are added each week. What is the rate of change, in coins per week? Write a negative number if it decreases.
14. A pool holds 77 L of water and a hose adds 12 L every minute. What is the rate of change, in L per minute? Write a negative number if it decreases.
15. A jar holds 107 coins and 16 more coins are added each week. What is the rate of change, in coins per week? Write a negative number if it decreases.
16. A pool holds 106 L of water and a hose adds 2 L every minute. What is the rate of change, in L per minute? Write a negative number if it decreases.
17. A candle is 41 cm tall and burns down 8 cm every hour. What is the rate of change, in cm per hour? Write a negative number if it decreases.
18. A candle is 186 cm tall and burns down 13 cm every hour. What is the rate of change, in cm per hour? Write a negative number if it decreases.
19. A pool holds 171 L of water and a hose adds 11 L every minute. What is the rate of change, in L per minute? Write a negative number if it decreases.
20. A hiker is 90 km from camp and walks toward it at 27 km every hour. What is the rate of change, in km per hour? Write a negative number if it decreases.